Opuntia plant named ‘Seleno-Purple’

ABSTRACT

A new and distinctly salt and boron tolerant cultivar of prickly pear ( Opuntia ficus - indica ), named ‘Seleno-Purple,’ is particularly distinguishable by its ability to tolerate and grow in high concentration of salt, boron and selenium-laden soil. The cultigen was originally discovered by stringent selection of randomly harvested cladodes (modified stems) and potentially from isolation of a single unique cladode or sport that exhibited high levels of salt and boron tolerance necessary for survival, and then propagated into the ‘Seleno-Purple’ cultivar. The cladodes were originally randomly harvested from different individual plants and screened from within a naturally segregating wild population or accession. The ‘Seleno-Purple’ cultivar has yellow flowers, mature green cladodes without glochids, and purple fruit. When grown in a saline/selenium-laden soil, the spineless ‘Seleno-Purple’ cultivar absorbs high concentrations of natural-occurring selenium, volatilizes selenium, and produces edible cladodes and fruit enriched with potential anti-carcinogenic forms of organic selenium.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Selection and Development of the ‘Seleno-Purple’ cultivar was sponsoredby federal research at the USDA-ARS and supported by State of Californiafunds in the form of grants from the California State University FresnoAgricultural Research Initiative and the California Department of WaterResources.

Latin name of the genus and species of the plant claimed: Opuntiaficus-indica.

Cultivar denomination: ‘Seleno-Purple’.

BACKGROUND OF THE INVENTION

1. Field of the Invention

In the last decade a large variety of individual plants from numerousaccessions of naturally occurring populations have been evaluated forsalt and boron tolerance and accumulation of selenium. These include;mustard and canola (Banuelos et al., 1998), poplar trees (Shannon etal., 1999), broccoli (Banuelos et al., 2003), birdsfoot trefoil (Steinerand Banuelos, 2003), and Indian Fig Opuntia (Banuelos and Lin, 2010)that were tested under typical poor quality soil conditions present inagricultural drainage sediment and in the Westside of the centralvalley. The identification of new crops is a prerequisite for theagricultural use of over 500,000 acres of fallowed and drought-strickenhypersalinized soils in the relevant region of California. Importantly,plants that are salt and boron tolerant and require minimum water, aretop priority for growers in this part of California.

2. Description of the Relevant Art

Opuntia ficus-indica cultivar selections have been previously identifiedand described (Felker et al., 2005; Parish and Felker, 1997). Four U.S.Plant Patents were issued for newly developed cactus pear varieties(U.S. Plant Pat. No. 21,760 P2, U.S. Plant Pat. No. 21,834 P2, U.S.Plant Pat. No. 21,964 P2, and U.S. Plant Pat. No. 22,077 P2). Opuntiaficus-indica is a species of cactus that produces edible fruit andcladodes. The fruits can have large distinct surface spines, small hairybarbed glochids, or be mostly spineless. They are grown in arid parts ofthe world, such as Central America, South America, Spain, Italy, Israeland South Africa (Parish and Felker, 1997).

Opuntia ficus-indica fruit and the succulent vegetative pads or cladodes(modified stems) have chemotherapeutic medicinal properties that whenconsumed, can reportedly help improve human immune and nervous systems,reduce oxidative stress through scavenging free radicals, treatgastritis, reduce hyperglycemia, reduce atherosclerosis, inhibitdiabetes and prostatic hypertrophy (enlarged prostate) (reviewed byFeugang et al., 2006). Uniquely, Opuntia ficus-indica fruit extracts arealso reported to inhibit the growth of human ovarian, cervical andbladder cancer cell lines, and reduce the high rate of tumor formationin carcinogen-stressed nude mice (Zou et al., 2005).

The medicinal chemotherapeutic effects are at least in part a result ofthe antioxidant phytochemicals or pigments concentrated in Opuntiaficus-indica fruit and these compounds may help provide protectionagainst multiple chronic human diseases. Polyphenolic flavonoids(quercetin, kaempferol and isorhamnetin), various carotenoids and thebetalains (betanin and indicaxanthin) in the fruit are previouslyreported to have a high rate of antioxidant activity. Additionally, thefruit are rich in ascorbic acid and contain high levels of amino acids,especially proline, taurine and serine (Feugang et al., 2006). Cladodesfrom the Opuntia ficus-indica plant are naturally-enriched in niacin(B3), amino acids and fiber, and are reported to prevent excess bloodsugar conversion into fat and lower total cholesterol, triglyceride andlow density lipid levels.

Moreover, they contain elevated concentrations of vitamins A, B, and C.Also, Opuntia ficus-indica contains the following minerals: calcium,magnesium, sodium, potassium, and iron (Feugang et al., 2006). AndOpuntia ficus-indica contains the following fibers: lignin, cellulose,hemicelluloses, pectin, mucilage's and gum form (Feugang et al., 2006).In addition, Opuntia ficus-indica contains 17 amino acids (Feugang etal., 2006). Organo-seleno forms are generally considered morebioavailable to antioxidant enzymes, i.e., selenoglutathione peroxidase(Stadtman, 1980), are easier to metabolize by humans, and are reportedto have greater anticarcinogenic activity (Ip & Ganther, 1992; Clark etal., 1996).

BRIEF SUMMARY OF THE INVENTION

The present invention relates to a salt and boron tolerant cultivar ofOpuntia ficus-indica named ‘Seleno-Purple.’ The ‘Seleno-Purple’ cultivarwas identified from a cladode selection process to produce a Opuntiaficus-indica cultivar that is salt and boron tolerant, and can surviveand readily accumulate selenium from the soils of the Western SanJoaquin Valley region of California. The ‘Seleno-Purple’ cultivarproduces yellow flowers, cladodes without glochids, and fruit andcladodes containing high levels of selenium. Also, the ‘Seleno-Purple’cultivar exhibits a selenium volatilization rate of betweenapproximately 38 μg/m²/day and approximately 43 μg/m²/day, when grown insoils containing a range of total selenium concentration fromapproximately 1.8 μg/g to approximately 5.3 μg/g. These traits have beenrepeatedly observed in asexually reproduced plants and are determined tobe basic characteristics of the new salt and boron tolerant‘Seleno-Purple’ cultivar.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the cladodes produced by the ‘Seleno-Purple’ cultivar.

FIG. 2 shows an opened flower produced by and growing on the‘Seleno-Purple’ cultivar.

FIG. 3 shows fruit produced by and growing on the ‘Seleno-Purple’cultivar.

DETAILED BOTANICAL DESCRIPTION

‘Seleno-Purple’ is a cultivar of Opuntia ficus-indica identified througha cladode screening and cultigen selection program. ‘Seleno-Purple’ isbest described as a sport or a mutant with a uniquely expressedgenotype, resulting in a phenotype allowing this unique individual totolerate high concentration salt and boron conditions. ‘Seleno-Purple’is a cultivar that was asexually propagated from a spineless cactus pear(Opuntia ficus-indica (L. Mill) cultigen, which was selected from acladode (stem) for its salt and boron tolerance from individualspecimens growing at the USDA-ARS National Arid Land Genetic ResourcesUnit in Parlier, Calif. and at Red Rock Ranch in Five Points, Calif.

1. Cultivar Selection

The ‘Seleno-Purple’ cultivar originated from a selection process to findsalt and boron tolerant spineless individual cladodes or cultigens fromapproximately 300 Opuntia ficus-indica cactus pear plants amongapproximately 100 different accessions (naturally-occurring out crossingpopulations) that were collected from around the world, includingaccessions from Mexico, Chile, Brazil, Spain and Italy. Theapproximately 900 spineless cactus pear cladodes were individuallyscreened in the greenhouse for their unique physiological ability totolerate salt and boron, while producing quality fruit under thesenormally agronomically “toxic” poor soil conditions. To do this,approximately 900 cactus pear cladodes were initially planted inagricultural drainage sediment (transported to USDA-ARS ResearchFacility from the San Louis Drain) high in salt and high boron in orderto stringently select for a cultigen with salt and boron tolerance atthe San Joaquin Valley Research Center under greenhouse and microplotgrowing conditions.

Cuttings from randomly selected cladodes were made from the few selectedsurvivors ˜3 and then used for continued selection and propagation inthe agricultural drainage sediment field microplots. These best threecultigens were allowed to grow into plants, which were monitored for anyexhibition of salt or boron toxicity symptoms, such as necrosis of theleaf cladodes, dark, discolored cladode edges, abscised cladodes/fruitor often whole plant death. Individuals exhibiting the characteristicsymptoms of salt and boron toxicity were noted and not chosen for futureuse.

Chemical properties of the agricultural drainage sediment within themicroplots comprise of a salinity level ranging from approximately 4decisiemens/m to approximately 6 decisiemens/m, soluble boron rangingfrom approximately 5 μg/ml to approximately 6 μg/ml, total seleniumranging from approximately 1.5 μg/g to approximately 5.5 μg/g, andextractable selenium ranging from approximately 0.5 μg/ml toapproximately 1.5 μg/ml in 0-50 cm soil. Control soil (without salinityand selenium) comprised of a Hanford sandy loam (coarse-loamy, mixedsuperactive, nonacid, thermic Typic Xerothents), with a salinity of <1decisiemen/m, total selenium of <0.1 μg/g, extractable selenium of <1μg/ml, and soluble boron of <0.1 μg/ml was used to compare“normal-grown” vs. agriculture drainage-grown Opuntia plants.

After 36-48 months, cuttings were then made of best two tolerant plants(cultigens) surviving in salt and boron-drainage sediment microplots.After three months of initial root establishment, at least two salt andboron tolerant individual plant cultigens were identified and grown toan older maturity in the microplots at San Joaquin Valley ResearchCenter, and harvested into individual cladodes or “cuttings”. These twotolerant cultivars were propagated by placing cuttings of cladodes—driedand dipped in copper sulfate fungicide—into pots containing potting soilmix without irrigation until new root and cladode sprouts appeared afterseveral weeks. The potted specimens were then lightly watered weeklywith ⅕ strength Hoagland's solution for two months in a greenhousebefore being hardened outside for one month. Once rooted in pots and newoffshoots emerged they were planted in mass (˜50 new plants) into thedrainage-impacted soils high in salt, boron, and selenium, located inthe harsh growing environment located at Red Rock Ranch under ariddrought, and high temperature conditions.

The environment at Red Rock Ranch is very dry, hot, and exposed to highlight intensity. The average summer (June-August) temperature at RedRock Ranch ranges from a high of approximately 35 degrees C. during theday to a low of approximately 16 degrees C. at night. The average wintertemperature (January and February) at Red Rock Ranch ranges from a highof approximately 12 degrees C. during the day to a low of approximately3 degrees C. at night. The relative humidity ranges from approximately28% to approximately 70% in the summer (June-August), and approximately70% to approximately 95% in the winter (January and February).Horizontal solar radiation averages approximately 8 kWh/m²/d in Julywith an annual total ranging from approximately 1.8 MWh/m² toapproximately 2.0 MWh/m². There is virtually no rainfall for four monthsfrom May through September, and evapotranspiration (ETo) remains highwith daily rates of approximately 7 mm (7 L/m²/d).

Red Rock Ranch has clay soils, containing high concentrations of salt(Na₂SO₄, NaCl, CaCl₂, Na₂SeO₄, CaSO₄, Na₂B₄O₅(OH)₄, and CaB₃O₄(OH)₃) andboron. The Red Rock Ranch soil composition is classified as an Oxalissilty clay loam (fine montmorillonitic, thermic Pachic Haploxeral) witha well-developed salinity profile. Soil salinity varies fromapproximately 4 decisiemens/m to approximately 8 decisiemens/m, whilesoluble boron varies from approximately 4 μg/ml to approximately 7μg/ml. The top 30 cm of soil contains between approximately 2 μg Se/gand approximately 4 μg Se/g of total selenium, and the extractableselenium concentrations range between approximately 0.8 μg Se/mL andapproximately 1.2 μg Se/mL.

Out of these ˜50 cladodes transplanted into soils at Red Rock Ranch, aunique cultigen, emerged as the best growing and highest fruit producingOpuntia ficus-indica plant that produces purple fruit. This individualcultigen, apparently a unique sport or offshoot, was then clonallyasexually propagated or cultivated as the most salt and boron tolerant‘Seleno-Purple’ cultivar, ideally suited for growth and fruit productionthe poor quality soils at Red Rock Ranch in the WSJV.

After 24 months, the ‘Seleno-Purple’ cultivar now thrives in thehypersalinized Red Rock Ranch harsh field environment. Under theseconditions, the ‘Seleno-Purple’ cultivar has large cladodes, grows verywell and produces large, firm fruit. ‘Seleno-Purple’ cultivar is madefrom a salt and boron tolerant sport cultigen of Opuntia ficus-indica.

2. ‘Seleno-Purple’ Cultivar Specification

The distinctive ‘Seleno-Purple’ characteristics described below arereproduced asexually, propagated by cladode cuttings and replanting asdescribed above. Color references are made to The Royal HorticulturalSociety Color Chart (R.H.S.) 2001. Most measurements are taken from the48-month old ‘Seleno-Purple’ cultivar plant, surviving in the harsh RedRock Ranch field environment, unless stated otherwise.

At two years old, the ‘Seleno-Purple’ cultivar measures approximately157 cm in height from the top of the plant to the soil level,approximately 141 cm in length from the tip of one cladode to the tip ofan opposing cladode along a straight length axis, and approximately 120cm in width from the tip of one cladode to the tip of an opposingcladode along a straight width axis, that is perpendicular to the lengthaxis.

As shown in FIG. 1, the ‘Seleno-Purple’ cultivar plant has a typicalcladode that is broad, flat, and oval shaped. The cladode is Green 137Cin color and the cladode surface has a smooth non-sticky texture. Thetypical cladode measures approximately 46 cm to approximately 47 cm inlength, approximately 24 cm to approximately 25 cm in width, andapproximately 2 cm to approximately 3 cm in thickness. The typicalcladode may have between 230 and 240 areoles per cladode. The areoles onthe cladodes are grey-orange group N167 A colored.

The cladode on 12-month old to 24-month old ‘Seleno-Purple’ cultivarplant may have very small glochids on the cladodes. On the 12-month oldto 24-month old ‘Seleno-Purple’ cultivar plant, there may be 10 to 50glochids per cladode, and each glochid may range from approximately 0.1mm to approximately 1 mm in length. Older ‘Seleno-Purple’ cultivarplants—which are those older than 24-months—have primarily only cladodeswithout any glochids. Therefore, the ‘Seleno-Purple’ cultivar may belabeled as a “spineless cultivar.”

As shown in FIG. 2, the ‘Seleno-Purple’ cultivar has petaled flowersmeasuring approximately 7 cm in diameter, with approximately 18 petalsthat are Yellow Orange N25 A colored on the petal interior and YellowOrange N30 C on the petal exterior. The flowers have no fragrance. Theflower petals are oval shaped. The ‘Seleno-Purple’ plant cultivarflowers from late July through mid-September and may be pollinated byhoney bees and cactus bees. There is one stigma per flower, and thestigma length ranges from approximately 3 mm to approximately 7 mm (withan average length of 5 mm). There are approximately between 300 stamensand 700 stamens per flower (with an average of between 400 stamens and500 stamens per flower), which range in length from approximately 300 mmto approximately 500 mm (with an average stamen length of about 400 mm).

As shown in FIG. 3, the ‘Seleno-Purple’ cultivar produces generallyovate-shaped fruit that are Purple N79 B colored on the exterior and 59Bto 65C colored in the interior. The fruit weighs approximately 130 g toapproximately 150 g (with an average weight of approximately 143 g).There are approximately 55 to 70 areoles per fruit (with an average ofapproximately 62 areoles per fruit). There are very few, if any glochidson the areoles. The average number of glochids per areole ranges from 0to approximately 3 (with an average number of glochids of 0 or 1). Thelength of the glochids range from approximately 0.1 mm to approximately1 mm. The fruit has peel thickness ranging from approximately 3 mm toapproximately 7 mm (with the average peel thickness being 5 mm).

The dry seed weight of the fruit ranges from approximately 1.7 g toapproximately 2.2 g (with an average weight of approximately 1.96 g).The fruit is harvested based on the color intensity and desiredfirmness.

The ‘Seleno-Purple’ cultivar contains a large amount of selenium in boththe cladodes and the fruit when grown in soil that has betweenapproximately 2 μg Se/g and 4 μg Se/g as total selenium in the upper 30cm. The ‘Seleno-Purple’ cultivar produced cladodes containing seleniumranging from approximately 8 μg Se/g and approximately 9 μg Se/g. Thefruit peel contains between approximately 1.7 μg Se/g and 1.9 μg Se/g.The fruit flesh contains between approximately 1.8 μg Se/g andapproximately 2.1 μg Se/g. The fruit seeds contain between approximately6.2 μg Se/g and 7.1 μg Se/g. Plant tissue concentrations of seleniumwill vary dependent upon fluctuating amounts of soluble selenium andsulfate (competes for selenium uptake) salts present in the soil. Soilselenium concentrations and forms of selenium naturally fluctuate overtime, as they are influenced by the soil environment.

In addition, the ‘Seleno-Purple’ cultivar volatilizes selenium, aprocess otherwise described as the plant releasing selenium in gaseousform from the plant and adjacent soil surface. This process slowlyremoves selenium from the soil in a non-toxic manner. During the peak ofsummer, (throughout the month of August), ‘Seleno-Purple’ volatilizesbetween approximately 38 μg Se/m²/day and approximately 43 μg Se/m²/daywhen grown under the already described soil condition.

The ‘Seleno-Purple’ cultivar differs in plant dimensions from otherknown Opuntia ficus-indica varieties. Table 1 shows the differencesbetween the ‘Seleno-Purple’ cultivar and the DAR 1-12-19 RED cultivar(U.S. Plant Pat. No. 21,760 P2). The ‘Seleno-Purple’ cultivar was grownin soil with high levels of salt and boron. The DAR 1-12-19 RED cultivarwas grown in conditions described in U.S. Plant Pat. No. 21,760 P2.

TABLE 1 ‘Seleno-Purple’ Compared to DAR 1-21-27 PURPLE ‘Seleno-Purple’DAR 1-21-27 PURPLE Average Plant Height (cm) 157 250 Average Plant Width(cm) 120 400 Average Flower Diameter (cm) 7 6 Average Fruit Weight (g)143 136.7 Average Cladode Length (cm) 46.4 40 Average Cladode Width (cm)24.4 32 Average Cladode Thickness (cm) 2.4 2.1

Besides differences in plant dimensions, due to its ability to surviveand thrive in high saline and boron soils, the ‘Seleno-Purple’ cultivaris able to accumulate substantial levels of selenium as shown in Table2.

TABLE 2 Comparison of selenium content in 48-month old ‘Seleno-Purple’cultivar when grown in soil containing between 2 μg Se/g and 4 μg Se/gin comparison to control soils. ‘Seleno-Purple’ ‘Seleno-Purple’ (withselenium) (without selenium) Selenium Content in Cladodes 8-9 0.1 (μgSe/g) Selenium Content in Fruit Peel 1.7-1.9 <0.1 (μg Se/g) SeleniumContent in Fruit Flesh 1.8-2.1 <0.1 (μg Se/g) Selenium Content in FruitSeeds 6.2-7.1 0.1-0.2 (μg Se/g) Selenium Volatilization Rate 38-43 <5During Summer (μg Se/m²/day)

Disease or pest resistance has not been properly observed in the‘Seleno-Purple’ cultivar. However, the other individual cultigens allsuffered both salt and boron toxicity in addition to an apparentpathogen susceptibility.

What is claimed is:
 1. A new and distinct salt and boron tolerant,selenium accumulating cultivar of Opuntia ficus-indica named‘Seleno-Purple,’ as substantially illustrated and described herein.